I say you're looking the wrong way at the 'desktop' form factor. It has a use - a very good one, which is so little explored. Personal cloud computing, basically. Instead of trusting some other company to compute and store data for you, you can invest in a good, ridiculously powerful for even five years ago, computer. Skip the monitor and keyboard and mouse - just keep them nearby if you ever need them for setup/reinstall. Just leave the thing idling away, set it up to have wake-on-lan, install SSH, VPN, VNC/Remote-Desktop, a virtual OS or two for stuff you can't get on the OS you're running natively, and the heavy-duty stuff that your mobile devices can't do gets redirected to it. Encrypt that connection and with IPv6 rolling out and computers - especially the desktop - becoming as cheap as they are to get high-end hardware for, you can soon have yourself personal 'super'-computers, doing your server and intense computing tasks from within your home, under your rules and your supervision, within your legal jurisdiction.

Hook up a bunch of old ones you have lying around, making a "beowulf cluster" as I see them getting called (one of my upcoming projects) and it goes from being just a heavy-hitter computing-wise in comparison to your mobile devices, to being a legitimate super-computer if the I/O and processing assignments are handled by your cluster properly. Again, the cluster's nodes can all have their own addresses courtesy IPv6, or internal ones (unlike home individual computers, a cluster is technically ONE unit, if it's actually being a cluster efficiently, so there's no need for external separate addresses anyway).

And if you're walking about and need to brute force a WAP2 key, say, for completely ethical reasons, like intercepting some illegally operating group's communications or what have you, bam, send that captured sucker over (whatever)G down to your home address, where you wake your computer / computer-cluster, and let it put it's combined power into cracking the sucker.

Hell, I haven't overclocked my N900 yet - but if I do, and it turns out even more powerful when overclocked (and the battery hotswap method, as well as the battery capacities of those battery shapes, are drastically improved), all I'd need is some greater feature support in FreOffice, portrait mode system-wide, an input method like 8-pen/qwo (that will catch on, unless electrotactile screens or something similarly innovative comes out, mark my words), printer drivers from Debian that work with my printers, and hell, I'm pretty much set. I'd love to see expandable RAM; it wouldn't surprise me if someone skilled enough COULD figure out how to solder a better-capacity RAM chip onto the N900's SoC from a later version of the OMAP SoC. *Shrug* Maybe not, but one can hope.

At any rate, if one actually has a beowulf cluster sitting at home, and internet connectivity there, the RAM requirement drops a bit.

Beyond that, I wouldn't MIND having a tablet or laptop, I love my video games like Crysis and StarCraft II and the like, but honestly, if I have an N900-like in versatility and broadness of capacity device, I don't really need those things, and I would be okay with not having them.